Improvement in altiscopes



J. CLARK.

Altiscope.

Patented March 13, 1866.

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PATENT JOHN CLARK, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN ALTISCOPES.

Specification forming part of Letters Patent No. 53,115, dated March 13,1866.

To all whom it may concern:

Be it known that I, JOHN CLARK, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and Improved Altiscope; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference beinghad to the accompanying drawings, forming part ot' this specification, in Which- Figure l represents a longitudinal vertical section of this invention, taken in the plane indicated by the line x w, Fig. 2. Fig. 2 is a similar section of the same, the plane of section being indicated by the line y y, Fig. l. Fig. 3 is a diagram, showing the manner in which the image -is formed.

Similar letters of reference indicate like parts.

The object of this invention is au instrument to be used as an observatory or lookout for viewing distant or near objects, as it' seen from an elevated point of view, to enable a person standing on the ground-as in the street, for instanceto look over the tops of the houses and see over the city and surround'- ing country in the same manner as if he was up on a high tower and looking through a telescope. Y

The invention consists in an instrument composed mainly of a hollow column, either stationary or revolving, with an opening in one side close to the top andV with an opening in the opposite side near the bottom, the said openings being fitted with oblique mirrors or reiiectors, either plane or concave, in such a manner that by the upper mirror the surrounding objects are reflected on the lower one and by said lower mirror the pictures are reflected through the lower opening, where they may be seen by an observer.

The invention consists, also, in the use of a telescope tube or column, in combination with two or more inclined reflectors, and with or without suitable lenses, in such a manner that the upper reflector can be raised higher or lower, as may be desirable, and that the same can be adjusted according to the object or objects to be retlected. The image of said objects is formed in that end of the tube farthest from the eye of the observer, and it is transA mitted to the opposite end of said tube by a ameter at the bottom and about six or seven inches at the top. This tube may be made of wood, metal, or any other suitable material,

and I do not wish to limit myself to any particular size or shape. It may be round, polygonal, or of any other suitable form or shape,

and constructed of any proper material and to any requisite size.

Near the top of the tube an opening, a, is made in one side, and a mirror or reiiector, b, is placed iu the tube opposite said opening at an angle of about forty-tive degrees. Near the bottom and at the opposite side of the tube is a similar opening, c, and a retlector, d,

is arranged opposite to said opening, also at I an angle of about forty-tive degrees. rlhe relectors b d may be plane mirrors, or, if desired, concave mirrors may be used. When this tube is placed in an erect position any object within range of the top mirror will be reflected down through the tube to the lower mirror and may be seen by looking through the lower opening, c. and of a comparatively small diameter, with nothing but plane reflectors, the view or field of vision would be very limited; but in order to venlarge the view and magnify the objects seen I use a certain arrangement of lenses different from anything I have seen in other optical instruments. I place iu the top of the tube an object-glass, f, of short focus, which forms an image in the tube of all objects reliected by the mirror. A short distance below this object-glass I place a second lens, g, of a long focus, which receives the image already formed and transmits it enlarged down through the tube. Near the bottom of the tube the enlarged image is intercepted by the lens It, which again eularges it and throws it on the mirror d, that reiiects it to the eye of the observer. (See Fig. 8.) By this arrangement a beautiful telescopic view can be obtained of the whole city and surrounding country for miles, if the tube is so constructed that it can be rotated on its own center.

If, for a plane mirror on the top, a concave mirror is substituted, the objectglass can be dispensed with, as the image will be formed If the tube is very long by said mirror and transmitted to the bottom of the tube by the lens g. If, in place ot the lower plane mirror, a concave mirror is substituted, the eyeglass or lens h can be dispensed with, and the instrument can be made of one lens and two curved mirrors.

Where the altiscope is intended to be used as a permanent lookout, or to be attached to a building or other structure, for looking over farms, &c, a single tube ot' the required length may be used. For a portable instrument it must be made in sections or joints that slide into each other in the manner of telescopetubes. v

The top mirror, b, is fastened with a hinge or center, so that it can be adjusted lto any, angle.

The second lens, g, next to the object-glass, is adjustable, and by this arrangement I am enabled to accommodate my lenses to any length ot' tube, because by moving the1 lens g.

up or down the image formed by the objectglass can be thrown to any distance required and will be enlarged to any size, depending on the distance thrown or the focus of the lens, or both.

A suitable mechanism may be applied to raise or lower the lens q from the ground, if the tube is made in sections.

The tube `may be furnished with a center,` which rests on a platform, or it may be ar-` ranged on a suitable turn-table, so that it can be rotated freely in either direction. y

When the tubes are arranged to extend in the manner of a telescope the several sections-are connected by cords v1, which extend over pulleys j, secured in the upperends of the several sections, as shown in Fig. l of the drawings, and a windlass, 7c, near the bottom end of the lowest section serves to raise and lower the tube.

It is obvious that the number of sections can be increased to any desired extent, and a tube can thus be obtained of any required length.

The cords extend from both ends of the windlass over the pulleys in the top of the rst or lowest section, and thence down to the lowest end of the second section. Two other cords extend from the bottom end of the rst section over the rollers in the top of the second section and down to the bottom end ot' the third section, and two more cords extend from the bottom end of the second section over the pulleys in the top end of the third section and down to the bottom end oi' the fourth section, and so on it' more than four sections are used. By this arrangement of the cords the several sections rise and fall simultaneously.

I do not wish to confine myself, however, to any particular mechanism for elevating the tubes; neither do `I confine myself to any particular number of sections or tofany peculiar arrangement of lenses. i

1f, in place of the lens or eyeglass at the bottom of the tube, a plate of ground glass is substituted,a large and beautiful picture ot' all objects within range of the top mirror will beformed onthe plate, and maybe viewed by looking into the lower mirror either with the naked eye or through a large eyeglass. lt thus becomes a very interesting camera-obscura, forming pictures of the landscape for miles around, and may be enlarged. or magnified to any extent, depending upon the arrangement of the lenses and the length of tube.

1 claim as new and desire to secure vby Letters Paten t Y Gombinin g with a telescopic column of tubes an arrangement of mirrors and lenses, such as is herein described, with provisions for adjusting these parts to any elevation ot` the tubes i desired, in the manner and `'or the purposes herein set forth.

1J OHN CLARK.

Witnesses W.' HAUFF, WM. DEAN OVERELL. 

